It is that time of the year again, actually it is that time of the “every four years” again. Because this year is a leap year, a year when everybody wakes up on March 1st only to remember that it is actually February 29th. So why is this a thing? Well the story of our calendar is one of intrigue and murder… Okay, maybe not murder, but there were Romans involved so we’re thinking at least one killing and probably a few orgies, but that’s not what we want to talk about today. Instead, let’s take a closer look at this thing we call a leap year. So step with us into the Quantum Leap Accelerator and vanish… Oh boy.
For almost the entirety of human history, we humans have been obsessed with keeping track of the year. To understand this obsession we need to leap back, and unlike Dr. Samuel Beckett, we need to go a little farther back than any one of our single lifetimes, or even that of our parents or great grandparents. Our leap takes us back to the dawn of human history when our ancestors needed to keep track of the seasons in order to survive. Winter meant cold, Summer meant hot, and Spring meant it was time for… well you know. As early as 9000 BCE, humans were using notches on wood and bones to keep track of lunar phases in order to correctly count out the year. It became even more important to keep track of these things when we moved from a hunter gatherer species to an agrarian one. We needed way to know when to plant and when to harvest, and that is when things got trickier.
Keeping track of the seasons by how many full moons you see is fine, but imprecise. Even the concept of a “day” is hard to measure as the amount of sunlight and darkness vary from place to place and day to day. It took ancient humans awhile to figure out that you need to calculate the length of a day from high noon to high noon. That is why ancient calendars often varied from region to region. As you might imagine winters are a lot longer in Siberia than they are in Greece. So what does all this have to do with a leap year? Well, according to Ziggy, the ancient Egyptians were among the first to calculate the 365-day length of a year, and among the first to realize that we needed a leap year in order to keep us on track.
You see the solar year or tropical year is actually 365.2422 days long. As you can imagine it can be hard to account for that extra -almost- a quarter of a day. Some ancient societies like ancient Rome and China originally adapted lunar calendars, which meant that each month was 29.5 days long, but that meant the full year came up 11 days short. Other civilizations, like the Sumerians just divided their calendar into 12 months of 30 days and were done with it. That was problematic too, because if you are good at math you might notice that only amounts to 360 days and even Al can tell you that is about a week short. Now, our ancestors were aware of this and some civilizations often declared week-long holiday festivals or other extra-calendar activities to try and keep the year on track, but it was sometimes messy, and we’re not talking about the feasts themselves.
Leaping on a String
By the time Julius Caesar came to power Rome’s calendar was off by about 4 months. September was in summer, February was in the fall, and so the Romans found themselves leaping from year to year, striving to put right what once went wrong, and hoping each time that their next year would be the leap home… or something like that. Thankfully, Caesar was walking like an Egyptian with Cleopatra and observed their 365-day long calendar, and realized its potential to fix Rome’s own quantum-related problems. First, he had to fix the time lag, so in 46 BCE he decreed the Year of Confusion, a 445-day long year meant to get the Roman calendar back on track. He then changed the calendar to a 365-day calendar -conveniently giving himself a month in the process- and every four years he declared it to be a leap year to account for that discrepancy of almost a quarter of the day.
Now we say “almost,” because if you remember it is only .2422 of a full day. So adding a full day ever 4 years actually adds too much time onto the calendar. That’s why 128 years later, the Romans and everyone else who were living by the Julian Calendar found themselves off the solar calendar by an extra day’s worth of time. Leaping forward to the 16th century this discrepancy had caused important Christian holidays to slide forward by ten days or so, and Pope Gregory XIII decided he wasn’t going to be having anymore of that. So in 1582 he unveiled his Gregorian Calendar. First he cut the month of October short by 10 days, to fix the immediate problem, because screw October. Then the Pope decreed that every 100 years would not be a leap year. So there was no leap year on the years of 1700, 1800, 1900, but we did have one in 2000. Here is where it gets complicated, because 100 year intervals that are divisible by 400 -we are not kidding- do not skip their leap year. If you think that fixed the problem completely, then hold onto your Pope hat because we need to leap again.
This time we are leaping to the future. The Gregorian Calendar isn’t perfect. Factor in that the Earth’s rotation is actually slowing down, which is part of the reason why we arbitrarily add leap seconds to the clock, and you get a system of telling time is only ever going to be “good enough.” In the future, our ancestors may choose to change the calendar and the leap year tradition, because in about 10,000 year the remaining discrepancies will start to show through again, but who knows. Maybe by that time we will need to find a new solar calendar that accounts for the orbits and rotations of many worlds and moon colonies, or we may all be dead. For now the Gregorian Calendar is the best we have. After all, the calendar year is merely a human construct meant to try and keep track of something that does not work by our clocks or calendars, and yet that fact has not stopped people from letting their imaginations run wild with the possibilities of the leap year.
The Leap Home
There is a lot superstition and frustrations that surround a leap year. For instance, being born on February 29th in a leap year is confusing. You either celebrate your birthday every four years or you have to do it on a calendar date that isn’t your actual date of birth, and other traditions have taken the day further. February 29th is sometimes associated with the day that women propose marriage to men, because for most of history women taking charge was crazy talk. Other people believed that the leap year ruins the natural cycle of things and such superstitions arose as the Scottish saying, “Leap year was ne’er a good sheep year.” Greeks thought that making contracts or getting married on a leap year doomed the union to failure, which may explain some of their current relationship problems with the rest of Europe. Some notable things about February 29th is that Superman was fictionally born on that day, and Hatti McDaniel famously accepted the first Oscar awarded to an African American. Also, in 1504 Christopher Columbus used a lunar eclipse on February 29th to scare a population of local natives into giving his men supplies and food. So, you know, its a mixed bag sort of day.
However, there is possibly no other day that lives in so much infamy and awe in our collective imaginations. A leap year is not something we see everyday, but regardless of our superstitions or superhero birthdays, we need February 29th. Without a leap year we would still all be trapped in the past facing mirror images of our seasons that are not our own. We have come a long way in our calendar and who knows what the future holds. We may never be fully rid of our own little quantum leap.